Door operating mechanism for dump cars



May 3, 1949. A. E. ZIMMER 2,469,220

DOOR OPERATING MECHANISM FOR DUMP CARS Filed July 1a, 1946 l N VEN TOR.

A TTORNEY.

Patented May 3, 1949 D003 OPERATING MECHANISM FOR DUMP CABS Albert E.Zimmer, Chicago, Ill., assignor to Enterprise Railway Equipment Company,Chicago, 111., a corporation of Illinois Application July 18, 1946,Serial No. 684,587

3 Claims.

This invention relates to improvements in door operating mechanism fordump cars.

The main object of the invention is to provide, in a mechanism foroperating hinged bottom doors of dump cars comprising a rotary liftingshaft and adjustable connections between the shaft and the door operatedthereby, simple and reliable safety means for restricting operation ofthe mechanism under abnormal conditions of adjustment of the partsthereof, thereby protecting the same against damage or breakage.

A more specific object of the invention is to provide in a dooroperating mechanism of the character set forth including a rotarylifting shaft and an adjustable connection between the lifting shaft andthe door, adapted to be wound on the shaft, positive stop means toprevent overwinding of the adjustable connection when the mechanism isout of proper adjustment.

Other objects of the invention will more clearly appear from thedescription and claims hereinafter following.

In the drawing, forming a part of this specification, Fig. 1 is alongitudinal, vertical, sectional view taken at one end of a dump car,illustrating my improvements in connection therewith, showing thelifting shaft and sloping end wall of the car at one side of the same insection and the connection between the shaft and the dump door inelevation. Fig. 2 is a view similar to Fig. 1, but illustrative ofconditions which may be brought about in a door operating mechanism ofthis character when no provision is made to prevent overwinding. Fig. 3is a detail perspective view of the stop member employed in myimprovements.

As illustrated in the drawing, my improved operating mechanism isparticularly adapted for bottom doors of dump cars and is of the typeillustrated in Patent No. 1,547,640, granted July 28, 1925, to ArgyleCampbell, which patent discloses a complete operating mechanism of thiskind and the arrangement thereof on the car, and reference may be had tothe same for an understanding of the general arrangement and structureof a door operating mechanism of the type in which my improvements areembodied.

Referring to Figs. 1 and 2 of the drawing, it indicates one of thecenter sills of a car and H the sloping end wall of the car body. Theusual rotary shaft 12 of the lifting mechanism is journaled in suitablebearing brackets, not shown, carried by the underframe of the car. Theshaft I2 carries a hub 13 provided with a pair of radially extendingarms l4, only one of which is shown in the drawing. A link or block I ispivotally connected to the outer ends of the arms l4 and a lockinghanger it having a hook-shaped upper end portion is, in turn, pivotallyconnected to the outer end of the link It. The hanger l6 has a dependingshank portion, which extends below the shaft l2 and is laterally offsetat its lower end in the direction of the shaft, forming a head if fromwhich are supported the usual set of two links it, only one of which isshown in the drawing. These links are designed to connect the hanger tothe respective doors at opposite sides of the corresponding end of thecar. These links are supported from the head of the hanger to swingabout axes at right angles to the axis of swinging movement of thehanger. As is the usual practice, the links 18, one of which is shown inFigs. 1 and 2 of the drawing, are disposed at opposite sides of thehanger i6 and are connected to the latter by a transversely extendingbar I!) pivotally supported on the hanger by a pin 20. Each link I8 isforked at its upper end, as indicated at 2!, to receive thecorresponding outer end of the bar l9 and is pivotally connected to thelatter by a pin 22. The lower end of this link is anchored to the bottomend of the corresponding dump door which is indicated by 23, the link l8having an eye member 24 threaded on the lower end of the link. The eyemember 24 is connected to a clevis 25 fixed to a projecting bracket 26at the bottom end of the door 23'. As is well known to those skilled inthis art, the screw and nut connection between the threaded eye member24 and the link l8 provides for adjustment in length of the connectionbetween the winding means on the shaft l2 and the door to secure properclosing of the door and take up slack occurring in service.

In this type of dump car, the door 23 is hinged at its upper or outerend and is swung upwardly to closed position when the lifting mechanismis operated through rotation of the shaft I2. In the closed position ofthe doors as shown in Fig. 1, the mechanism is locked by the hook-shapedend of the hanger it being engaged over the hub l3, the weight of thedoors and lading of the car being carried on the shaft l2. Thearrangement is such that the direction of downward pull is in a straightline, indicated by A-A, passing through the shaft 12 at a point slightlyover dead center, thereby assuring a perfect look at all times andplacing the minimum strain on the various parts of the mechanism.

To prevent overthrow of the winding mechanism, that is, winding thereofbeyond the position shown in Fig. 1, I provide a stop member 33 mountedon each center sill ID of the car and arseated on the center sill l andis secured to the.

top flanges of the latter by rivets, 31 extending. through openings 32in the bottom wall 21' of the box and aligned openings in the flanges ofthe center sill. The stop member-.33 positivelyarrests movement of theparts in the positionsl'rown in Fig. 1 by engagement of the arms [4 ofthe Winding means therewith, thereby preventing. overwinding. In otherwords, regardless of the adjustment in length of the connecting meansbetween the lifting shaft l2 and the drop door 23, rotation of the.shaft 12 will always be limited so that. it. can-not. be turned beyondthe position shown in Fig. 1. in proper adjustment to fully close thedoors when the shaft I2 is rotated to the position shown in- Fig. 1 therotation of. the shaft is positively stopped to prevent overthrow of theWinding. means which would be serious because of possible damage to theworking parts of the mechanism. Overthrow of the lifting and windingmechanism is a constant danger in door operating mechanisms of thischaracter not provided with my improved stop means and frequentlyresults in. serious damage to the parts thereof, par-- ti'cularly thehanger and the lifting shaft; Conditions which prevail when there isoverthrow of the lifting mechanism are illustrated in Fig. 2, whereinthe shaft I? has been rotated beyond the position shown in Fig. 1, thatis, through a greater are to bring the drop doors 2'3 in proper relationto the car body to close said doors. A severe strain is thus placed onthe parts of the mechanism due to lever action at the point B, whichlever action may cause distortion and breakage of the hanger H3 or causetwisting of the lifting shaft [2. The force diagram traced by the linesconnecting the points D, E; and F, in Fig. 2; is indicative of theforceproducing the leverage at the point B.

As hereinbefo-re pointed out, any possible danger of overthrow of thelifting mechanism is completely eliminated by my improved stop means,the same limiting rotation of the liftin means to a predeterminedamount, as illustrated in Fig. 1. Thus, when there is any misadjustment'of the mechanism due to lengthening of the connections between the shaftl2 and the door 23, or due to greater movement of the door beingrequired to close the same, rotation of the mechanism is positivelystopped even though the door is not completely closed. The attendant isthus forced to Thus, if the mechanismfis not Y 4 adjust the liftingmechanism to proper overall length for lifting the door to its correctclosed position in relation to the car body. This adjustment is made inthe usual manner by manipulation of the screw and nut connection betweenthe link l8 and threaded eye member 24.

Iclaim:

.1. In a door operating: mechanism for dump cars having a hinged bottomdoor, a rotary liftin shaft supported on the car, a radial arm on saidshaft, and link means inter-connectin the door with and pivotallyconnected to the radial arm, the improvement which comprises a stopmember-located in the path of rotary movement of the radial arm'. in aposition adjacent the point where the pivotal connection between thelink means. and the radial arm is located when the door is in closedposition whereby over-winding of the link means and resulting damage tothe operating parts are prevented.

2. In a. door operating; mechanism for dump cars having a hinged bottom.door, a rotary li-f-t-= ing shaft supported on the car, a radial arm onsaid. shaft, and link: means inter-connecting the door with. the radialarm, the improvement which comprises the combination of a link, being apart. of said link means and beingv pivotally connected: to said radialarm, and a stop member located in the path of rotary movement of theradial: armin a position adjacent the point where the pivotal connectionbetween. the linkand the radial. arm. is located. when the door isclosed: position whereby over winding, of the; link. means. andresulting damage;- to thev operating. parts arev prevented.

3:. In a door operating mechanism for dum i cars. having a hinged bottomdoor, a rotary lifting shaft supported on; the car, a. radial arm onsaid shaft, and link means. inter-connecting; the door with the radialarm. the improvementwhich comprises the-combination of a. link, being.apart of said link means, being pivotally connected to said radi'alarmand; extending; upwardly when the door is: in. closed position,v and. astop member located in the. path of rotary movement of the radial arm ina. position belowthe point where the pivota-l connection between thelink and the radial arm is located when the door is in closed positionwhereby over-winding of the link means and resulting damage" to theoperating parts are pre vented.

ALBERT E. ZIMMER'.

REFERENCES CITED The following references are of record in the. file ofthis patent:

ITED- STATES PATENTS Number Name Date.

1,095,241 Summers May 5,. 1914. 1,547,640 Campbell July 28, 1925

